Power transmitting element



Dec. 27, 1966 GROB 3,293,884

POWER TRANSMITTING ELEMENT Original Filed Aug. 5, 1961 2 Sheets-Sheet 1JNVENTOR. .5512 2 1771 51 027 BY 4 \74ndrus Star/(g A iiarm ys Dec. 27,1966 B. GROB 3,293,884

POWER TRANSMITTING ELEMENT Original Filed Aug. 5, 1961 2 Sheets-Sheet $3$3 INVEN'IOR.

5517 3mm Erab N. BY 0 74ndr'us Star/(g United States Patent Ofiice3,293,884 Patented Dec. 27, 1966 3,293,534 POWER TRANSMZTTENG ELEMENTBenjamin Grob, Grafton, Wis, assignor to Grob Inc., Grafton, Wis., acorporation of Wisconsin Original application Aug. 3, 1961, Ser. No.129,073. Divided and this application Sept. 1, 1965, Ser. No. 484,269

2 Claims. (Cl. 64-23) This application is a division of applicantscopending application Serial No. 129,073, filed August 3, 1961, and nowabandoned.

This invention relates to an axially grooved power transmitting elementof tubular form.

The invention is adapted for general use in the formation of axiallyextending gear teeth, splines or grooves in either the external orinternal surface of a tubular element that cooperate with a similarlycontoured member to transmit power.

The basic concept of the present invention resides in the use, as apower transmitting element, of a tubular member having gear teeth,splines or grooves formed in either the external or internal surfacethereof by a cold forming process which effects the finished contouredform of the teeth, splines or grooves by deformation of the tubularmember without the removal of material therefrom.

An object resides in the provision of a new and improved powertransmitting coupling composed of a pair of telescopically arrangedtubular member in which circumferentially spaced axially extendingmatching teeth,v

splines or grooves are formed on the adjacent surfaces of the housingand housed members by a repetitive cold forming process in which nomaterial is removed from either member.

Another object resides in the provision of a new and improved powertransmitting coupling composed of a pair of telescopically arrangedtubular members in which the circumferentially spaced axially extendingmatching teeth, splines or grooves on the adjacent surfaces of thehousing and housed members are produced by a repetitive cold formingprocess and are in finished form at the completion of the formingoperation.

Other objects and advantages, either expressed or implied, will becomeapparent from the following description of an illustrative embodiment ofthe present invention.

In the drawings:

FIG. 1 is a top plan view of a power transmitting coupling constructedin accordance with the teachings of the present invention;

FIG. 2 is a fragmentary vertical longitudinal sectional view takenthrough the assembled splined inner and outer tubes of a powertransmitting coupling;

FIG. 3 is a vertical transverse sectional view taken substantially onthe line 33 of FIG. 2 showing the relative positioning between thesplined portion of the telescopically arranged tubes that form the powertransmitting connection therebetween; and

FIG. 4 is a vertical transverse sectional view taken on line 44 of FIG.2 showing the relationship between the unsplined portions of thetelescopically arranged tubes.

The'present invention is predicated, in part, on the disclosurecontained in US. Letters Patent No. 2,715,846 issued on August 23, 1955to Ernst and Benjamin Grob. The subject patent was directed to a methodof incrementally forming circumferentially spaced axially extendinggrooves in the outer surface of a solid cylindrical body. The desiredcross-sectional form of the grooves was dictated solely by the selectedcross-sectional form of the ribbed rollers that respectively applied apenetrating rolling force on surface of the solid cylindrical body.

While the present invention utilizes the cold rolling process disclosedand claimed in the above-mentioned patent, it constitutes an improvementthereon by reason of the fact that the present invention affords a newand improved axially grooved tubular power transmitting element in whichthe circumferentially spaced axially extending teeth, splines or groovesmay be selectively formed in either the inner or outer surface of atubular member. In the practice of the present invention, the form ofthe teeth, splines or grooves, selectively formed in the inner or outersurface of the tubular member requires the cooperative relationshipbetween circumferentially spaced axially extending grooves in aworkpiece supporting mandrel and the surface of the means by whichdeforming pressure is repetitively applied to the outer surface of thetubular member.

The embodiment of the present invention, chosen for illustrativepurposes, in FIGURE 1 of the accompanying drawings, comprises apropeller shaft 10 that serves as a connecting member between a pair ofuniversal joints 11 and 12 that form a portion of a power transmissionin a motor vehicle.

The propeller shaft 10 is composed of a pair of telescopically arrangedtubular members 13 and 14 respectively forming housing and housed tubes.One end of the housed member 14 is fixedly attached to one element ofthe universal joint 11 with the free end thereof slidably receivable inthe tubular member 13 which has one of its ends fixedly attached to oneelement of the universal joint 12.

The tubular members 13 and 14 are respectively provided with matchingsplines 15 and 16 to permit the required relative axial movement betweenthem in the power transmission.

The inner end portion of the outer tubular member 13 is swaged inwardlyto form a bearing surface 17 which is in engagement with the outersurface of the inner tubular member 14 and rides along the member 14 asthe tubular members slide or telescope relative to each other.

As best shown in FIG. 2, the end of outer tubular member 13 is bentoutwardly, defining an internal recess or groove which houses an annularseal 18.

In addition, an annular seal 20 can be located on the inner end of innertubular member 14 and is retained in position by a cap 21 which issecured to the end wall 22 of tubular member 14 by screw 23. Seal 20prevents the entry of foreign material between the tubular members 13and 14.

Spline 15 in outer member 13 has a substantially smaller axial lengththan spline 16 in the inner member 14, as illustrated in FIG. 2. Thisconstruction, in which spline 15 is smaller in length than spline 16,enables the propeller shaft to have substantial axial movement and yetthe length of contact between the tubular members in the splined area islimited so that the tendency of the member to bind under heavy torque isminimized.

The tubular members 13 and 14 are in contact with each other only at thearea of the spline 15 and at the location of the bearing 17, and thetubular members are spaced apart, as shown in FIG. 2, at locationsbetween these two positions of contact. As bearing surface 17 is spaceda substantial distance along the length of tube 13 from the spline 15,increased rigidity is provided, thereby enabling the tubular members totelescope with long axial movement without kinking or binding. This is adistinct advantage over the ordinary splined propeller shaft which hasonly limited telescopic movement because the area of contact between themembers constitutes only the short length of spline.

The use of the hollow tubular members 13 and 14 provides distinctadvantages in the design of a vehicle propeller shaft over the use ofbar stock which is machined to provide the spline connection. Torque isbest transmitted by tubular members, for under heavy reverse torque loadand side load, the relatively large diameter tubular members will moreeffectively resist the stress and increase the duration of use beforefailure. Moreover, due to the inherent elasticity of a tubular member,the spline teeth can retreat or push out under torque load so that allof the spline teeth will be in engagement and take the load regardlessof any possible inaccuracy in the formation of the teeth.

While the invention has been described in considerable detail in theforegoing specification, it is to be understood that various changes maybe made in its embodiment without departing from or sacrificing any ofthe advantages hereinafter claimed.

I claim:

1. A power transmitting coupling, comprising a tubular housing memberhaving a substantially uniform Wall thickness throughout its length andhaving an internal and external spline, a tubular housed member having asubstantially uniform wall thickness throughout its length and having aninternal and external spline, the inner end of the housed member beingtelescopically disposed within the inner end of the housing member andthe internal spline of said housing member matching and engaging theexternal spline of said housed member, the spline of said housing memberhaving a substantially shorter axial length than the spline of saidhoused member, and universal joint means secured to the outer end ofeach of said tubular members, the inner end portion of the housingmember being deformed radially inward to define an annular bearingspaced axially from the spline on said housing member, said housingmember and housed member being in contact with each other at thelocation of the matching splines and at the location of the bearing andspaced out of contact between the location of said matching splines andsaid bearing.

2. A power transmitting coupling, comprising a tubular outer housingmember having a substantially uniform wall thickness throughout itslength and including a generally cylindrical section and a splinedsection, a tubular inner housed member slidably disposed within theouter housing member and having a substantially uniform wall thicknessthroughout its length and including a generally cylindrical section anda splined section, the external diameter of the cylindrical section ofthe inner housed member being smaller than the internal diameter of theouter housing member to provide a clearance therebetween, the splinedsection of the outer housing member having a substantially shorter axiallength than the splined section of the inner housed member and saidsplined sections being in mating engagement, the diameter of the outerperiphery of the splined section of the inner housed member beingsubstantially equal to the external diameter of the cylindrical sectionof the inner housed member, the splines in the splined section of theouter housing member comprising a series of alternate ribs and groovesand the radial distance from the top of the ribs to the bottom of thegrooves being greater than the width of said clearance, and a bearinglocated on the inner surface of the cylindrical section of the outerhousing member and disposed in engagement with the outer surface of thecylindrical section of the inner housed member, said bearing beingspaced axially a substantial distance from the splined section of theouter housing member.

References Cited by the Examiner UNITED STATES PATENTS 1,644,800 10/1927Urschel 64-17 1,844,257 2/1932 Lincoln 6423 2,067,282 1/1937 Padgett 6412,072,090 3/1937 Anderson 64--23 X 2,116,290 5/1938 Spicer 6 23 FRED C.MATTERN, JR., Primary Examiner.

HALL C. COE, Examiner.

1. A POWER TRANSMITTING COUPLING, COMPRISING A TUBULAR HOUSING MEMBERHAVING A SUBSTANTIALLY UNIFORM WALL THICKNESS THROUGHOUT ITS LENGTH ANDHAVING AN INTERNAL AND EXTERNAL SPLINE, A TUBULAR HOUSED MEMBER HAVING ASUBSTANTIALLY UNIFORM WALL THICKNESS THROUGHOUT ITS LENGTH AND HAVING ANINTERNAL AND EXTERNAL SPLINE, THE INNER END OF THE HOUSED MEMBER BEINGTELESCOPICALLY DISPOSED WITHIN THE INNER END OF THE HOUSING MEMBER ANDTHE INTERNAL SPLINE OF THE HOUSING MEMBER MATCHING AND ENGAGING THEEXTERNAL SPLINE OF SAID HOUSED MEMBER, THE SPLINE OF SAID HOUSING MEMBERHAVING A SUBSTANTIALLY SHORTER AXIAL LENGTH THAN THE SPINE OF SAIDHOUSED MEMBER, AND UNIVERSAL JOINT MEANS SECURED TO THE OUTER END OFEACH OF SAID TUBULAR MEMBERS, THE INNER END PORTION OF THE HOUSINGMEMBER BEING DEFORMED RADIALLY INWARD TO DEFINE AN ANNULAR BEARINGSPACED AXIALLY FROM THE SPLINE ON SAID HOUSING MEMBER, SAID HOUSINGMEMBER AND HOUSED MEMBER BEING IN CONTACT WITH EACH OTHER AT THELOCATION OF THE MATCHING SPLINES AND AT THE LOCATION OF THE BEARING ANDSPACED OUT OF CONTACT BETWEEN THE LOCATION OF SAID MATCHING SPLINES ANDSAID BEARING.